Field of the Invention
The present invention relates to a wide angle lens and an imaging apparatus. In particular, the present invention relates to a wide angle lens that is usable in a camera for a mobile terminal, an in-vehicle camera or the like and especially appropriate for a surveillance camera, and also to an imaging apparatus including this wide angle lens.
Description of the Related Art
The size and the cost of kinds of lenses mountable on cameras in the aforementioned fields rapidly reduced in recent years. Especially, use of many plastic lenses has contributed to reduction in the size and the cost of the lens system.
As conventional lens systems using plastic lenses, lens systems disclosed, for example, in Japanese Unexamined Patent Publication No. 2009-288300 (Patent Document 1), Japanese Unexamined Patent Publication No. 2007-249073 (Patent Document 2), and PCT Japanese Publication No. 2004-523000 (Patent Document 3) are known. Patent Document 1 discloses a 6-element fish eye lens in which a glass lens is arranged closest to the object side and all the other lenses are plastic lenses. Patent Document 2 discloses a 6-element fish eye lens in which the first lens and the third lens from the object side are glass lenses and the other four lenses are plastic lenses. Patent Document 3 discloses a 6-element or 7-element lens system in which a plastic lens is arranged closest to the object side and all the other lenses are glass lenses, and an 8-element lens system in which the first lens and the second lens from the object side are plastic lenses and the other lenses are glass lenses.